JPH08334905A - Removing solution composition for resist - Google Patents

Abstract

PURPOSE: To obtain a removing soln. compsn. having a low viscosity, excellent in degenerated film removing property and enhancing corrosion preventing effect by incorporating N,N-diethylhydroxylamine, hydroxylamine, a water-soluble org. solvent, an anticorrosive and water in a specified ratio. CONSTITUTION: This removing soln. compsn. contains 2-30wt.% N,N-diethyl- hydroxylamine, 2-40wt.% hydroxylamine, 10-80wt.% water-soluble org. solvent, 1-20wt.% anitcorrosive and 2-30wt.% water. The N,N-diethylhydroxylamine is a compd. represented by N(C2 H5 )2 OH, the hydroxylamine is a compd. represented by NH2 OH and the water-soluble org. solvent is an org. solvent miscible with water, e.g. dimethylsulfoxide because the compds. exist as an aq. soln. The anti-corrosive is preferably selected from among arom. hydroxy compds. such as phenol and pyrocatechol, acetylene alcohol, a carboxyl group- contg. org. compd., its anhydride, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist stripping composition, and more specifically, it is excellent in stripping property and anticorrosive property, which is preferably used for manufacturing semiconductor elements such as IC and LSI or liquid crystal panel elements. At the same time, it relates to a resist stripping composition having a low viscosity and a long stripping life.

[0002]

2. Description of the Related Art Semiconductor elements such as ICs and LSIs and liquid crystal panel elements are provided with a uniform photoresist on a conductive metal film such as aluminum, copper or aluminum alloy formed on a substrate or an insulating film such as a SiO ₂ film. After coating, exposing and developing this to form a resist pattern, and using the pattern as a mask to selectively etch the conductive metal film or insulating film to form a fine circuit, an unnecessary resist layer is formed. It is manufactured by removing with a stripper.

As a stripping solution for removing this resist layer,
Conventionally, an organic sulfonic acid-based stripping solution containing an alkylbenzene sulfonic acid as an essential component and an organic amine-based stripping solution containing an organic amine such as monoethanolamine as an essential component have been used. The former organic sulfonic acid-based stripping solution has poor workability because it is used in combination with highly toxic organic compounds such as phenol compounds and chlorobenzene, and also causes environmental problems, and corrodes the conductive metal film of the substrate. It has the drawback that it is easy to get rid of. On the other hand, the latter organic amine-based stripping solution is less toxic than the organic sulfonic acid-based stripping solution, does not require complicated processing for waste liquid processing, and is formed by processing such as dry etching, ashing, and ion implantation. It is widely used today because of its excellent releasability of the deteriorated film and excellent corrosion prevention effect of the substrate containing Al, Cu and the like.

However, the processing conditions such as dry etching, ashing, and ion implantation adopted in today's semiconductor device and liquid crystal device manufacturing processes become strict, and the resist film after processing is changed from an organic film to a film having an inorganic property. It began to change. Therefore, even if treated with an organic amine-based stripping solution, the deteriorated film cannot be stripped sufficiently, and the treatment temperature of the organic amine-based stripping solution is 60 to 13
Due to the relatively high temperature of 0 ° C., there is a risk that the flammable organic compound in the stripping solution will volatilize and catch fire. Therefore, the peeling process is generally carried out in a fire prevention facility, and not only the facility for that purpose requires a large amount of cost, but also a long processing time and high throughput (the number of wafers processed per unit time) are required. As a stripping solution for semiconductor elements and liquid crystal panel elements to be used, it is no longer satisfactory. Therefore, there has been a demand for the appearance of a resist stripping solution that is more excellent in stripping the deteriorated film formed by the treatments such as dry etching, ashing, and ion implantation under more severe conditions. Further, from the viewpoint of prevention of ignition, a resist stripping solution having a low stripping temperature and capable of stripping in a short time has been desired.

Under these circumstances, a resist stripping solution comprising an organic amine such as monoethanolamine, water and a water-soluble organic solvent is disclosed in JP-A-57-165834 and 64-81949. Gazette, JP-A-64-8
It is proposed in Japanese Patent No. 1950 and Japanese Patent Laid-Open No. 64-88548. Since these stripping solutions contain water, the strippability of the above-mentioned deteriorated film is somewhat improved, and stripping at low temperatures is also possible, but it has not reached a sufficient level,
Further, the inclusion of water causes a problem that the corrosion of the substrate containing Al or Cu becomes large.

On the other hand, among organic amines, a resist stripping solution using hydroxylamines is disclosed in JP-A-4-28.
It is proposed in Japanese Patent No. 9866 and Japanese Patent Laid-Open No. 6-266119. A resist stripping solution using such a hydroxylamine is excellent in stripping ability as compared with a stripping solution using a conventional organic amine such as the above monoethanolamine, and thus is preferable.

The stripping solution described in JP-A-4-289866 mentioned above contains hydroxylamine and alkanolamine as essential components, but in reality, hydroxylamine cannot be obtained unless it is an aqueous solution. It will be a three component system of amine, alkanolamine and water. However, as described above, if water is contained, the corrosion of the substrate containing Al or Cu becomes large. Therefore, in order to suppress the corrosion of the metal substrate, a chelating agent (corrosion inhibitor) such as catechol must be further contained. It cannot be used practically.

A stripping solution further containing such a chelating agent is described in JP-A-6-266119. However, the resist stripping solution composed of hydroxylamines, alkanolamines, water, and chelating agents described in the publication has a problem that the viscosity thereof is higher than that of conventionally used stripping solutions. The stripping treatment is usually performed by immersing a silicon wafer having a resist layer in a stripping tank containing a stripping solution, and the stripping solution in the stripping tank is circulated through a pipe with a filter. Therefore, when the viscosity of the stripping solution becomes high, the circulation of the stripping solution is delayed, and there is a problem that throughput is reduced. Further, there is a problem in that it costs a lot of money to newly provide a stripping tank for a stripping solution having a viscosity higher than that of a conventional organic aminine stripping solution such as monoethanolamine. Furthermore, a resist stripping solution consisting of hydroxylamines, alkanolamines, water, and a chelating agent has a short stripping life because water content is reduced by evaporation of water during heating during stripping processing, leading to a reduction in stripping ability. There's a problem.

Therefore, under the present circumstances, it is desired to develop a stripping solution for an organic amine resist which has excellent strippability, has a viscosity equivalent to that of a conventional stripping solution, and has a long stripping life. .

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to modify by a process such as dry etching, ashing, or ion implantation under more severe conditions. Excellent film peeling property,
A resist stripping composition for resists, which is excellent in the corrosion prevention effect of a substrate on which a metal film such as Al, Cu, Ti or W is formed, has the same low viscosity as a conventional resist stripping solution, and has a long stripping life. To provide.

[0011]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that N, N-diethylhydroxylamine and hydroxylamine are contained in a predetermined amount to achieve excellent peeling. It was found that the viscosity can be suppressed to a low level as in the conventional one while maintaining the property, and further, the evaporation life of the water during the peeling treatment can be suppressed to prolong the peeling life, and the present invention is based on this. It came to completion.

That is, according to the present invention, (a) N, N-
Diethyl hydroxylamine 2 to 30% by weight, (b) hydroxylamine 2 to 40% by weight, (c) water-soluble organic solvent 10 to 80% by weight, (d) anticorrosive agent 1 to 20% by weight, and (e) water 2 Provided is a resist stripping solution composition comprising about 30% by weight.

The resist stripping composition for resist of the present invention is described in detail below.

N, N-diethylhydroxylamine as the component (a) is a compound represented by N (C ₂ H ₅ ) ₂ OH, and is compounded in a proportion of 2 to 30% by weight in the total amount of the composition of the present invention. However, it is more preferably 5 to 20% by weight.
If it is less than 2% by weight, the peeling ability is reduced, while 30% by weight
If it exceeds, the peeling effect cannot be obtained for the blending amount and the cost becomes high, which is not preferable.

Hydroxylamine as the component (b) is a compound represented by NH ₂ OH and is compounded in the composition of the present invention in an amount of 2 to 40% by weight, preferably 5 to 30% by weight. Is. If it is less than 2% by weight, the peeling ability is lowered. On the other hand, if it exceeds 40% by weight, no effect can be obtained for the compounding amount and the cost is increased, which is not preferable.

In the present invention, the component (a) and the component (b)
By mixing the components with the above-mentioned blending amount, the evaporation ability of water during the peeling treatment is small, so that the peeling ability is not deteriorated and the peeling life can be extended. The reason for this is not clear, but it is considered that the components (a) and (b) form an azeotropic mixture, which is probably to maintain the blending ratio of both components.

The water-soluble organic solvent of the component (c) may be any organic solvent that is miscible with water because the components (a) and (b) are present as an aqueous solution, and the conventional organic amine-based stripping solution. Any water-soluble organic solvent used in can be used. Examples of such water-soluble organic solvents include sulfoxides such as dimethyl sulfoxide; sulfones such as dimethyl sulfone, diethyl sulfone, bis (2-hydroxyethyl) sulfone, tetramethylene sulfone; N, N-dimethylformamide, N-methyl. Amides such as formamide, N, N-dimethylacetamide, N-methylacetamide, N, N-diethylacetamide; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N -Hydroxymethyl-2-pyrrolidone, N-hydroxyethyl-
Lactams such as 2-pyrrolidone; 1,3-dimethyl-2
-Imidazolidinones such as imidazolidinone, 1,3-diethyl-2-imidazolidinone and 1,3-diisopropyl-2-imidazolidinone; γ-butyrolactone, δ
-Lactones such as valerolactone; ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether , And polyhydric alcohols such as diethylene glycol monobutyl ether and derivatives thereof. Among these, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide,
N-methyl-2-pyrrolidone, 1,3-dimethyl-2-
Imidazolidinone and diethylene glycol monobutyl ether are preferable because they are excellent in resist releasability. These may be used alone or in combination of two or more.

The component (c) is mixed in the composition of the present invention in an amount of 10 to 80% by weight, preferably 20 to 70% by weight. If it is less than 10% by weight, the releasability of the resist film is poor, the flash point of the stripping solution is low, the stripping solution becomes difficult to handle, and the cost is high.
If it exceeds 80% by weight, the peeling ability is deteriorated, which is not preferable.

As the anticorrosive agent as the component (d), any anticorrosive agent used in a conventional organic amine-based stripping solution can be optionally used. In particular, an aromatic hydroxy compound,
At least one selected from the group consisting of acetylene alcohol, a carboxyl group-containing organic compound and its anhydride, and a triazole compound is preferably used.

Examples of the aromatic hydroxy compound include phenol, cresol, xylenol, pyrocatechol, resorcinol, hydroquinone, pyrogallol,
1,2,4-trihydroxybenzene, salicyl alcohol, p-hydroxybenzyl alcohol, o-hydroxybenzyl alcohol, p-hydroxyphenethyl alcohol, p-aminophenol, m-aminophenol, diaminophenol, aminoresorcinol, p-
Hydroxybenzoic acid, o-hydroxybenzoic acid, 2,4
-Dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid and the like can be mentioned, and among them, pyrocatechol is preferable. These compounds may be used alone or in combination of two or more.

As the acetylene alcohol, 2-
Butyne-1,4-diol, 3,5-dimethyl-1-hexyn-3-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol, 3,6
-Dimethyl-4-octyne-3,6-diol, 2,
4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol and the like can be mentioned, among which 2-butyne-1,4.
-Diols are preferred. These acetylene alcohols may be used alone or in combination of two or more kinds.

Examples of the carboxyl group-containing organic compound and its anhydride include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, benzoic acid and phthalic acid. acid,
1,2,3-benzenetricarboxylic acid, glycolic acid,
Lactic acid, malic acid, citric acid, acetic anhydride, phthalic anhydride,
Maleic anhydride, succinic anhydride, salicylic acid, etc. can be mentioned. Among them, formic acid, phthalic acid, benzoic acid, phthalic anhydride and salicylic acid are preferable, and phthalic acid, phthalic anhydride and salicylic acid are particularly preferable. These compounds may be used alone or in combination of two or more.

Examples of the triazole compound include benzotriazole, o-tolyltriazole, m-tolyltriazole, p-tolyltriazole, carboxybenzotriazole, 1-hydroxybenzotriazole,
Examples thereof include nitrobenzotriazole and dihydroxypropylbenzotriazole, and among them, benzotriazole is preferable. These compounds may be used alone or in combination of two or more.

These anticorrosive agents are used in the resist composition used,
One kind or two or more kinds may be appropriately used in combination depending on the stripping conditions, the conditions for forming a resist-altered film by ashing, ion implantation, plasma treatment or the like, the conditions for rinsing treatment in the subsequent step, and the like. An aromatic hydroxy compound ,
Acetylene alcohol is more preferably used, and among them, pyrocatechol and 2-butyne-1,4-diol are particularly preferable.

The component (d) is contained in the composition of the present invention in an amount of 1 to 20% by weight, preferably 2% by weight.
10 to 10% by weight. If it is less than 1% by weight, the anticorrosion effect becomes small and the corrosiveness against the substrate having the metal film becomes large, which is not preferable. On the other hand, if it exceeds 20% by weight, the peeling ability is deteriorated, which is not preferable.

Water as the component (e) is inevitably contained in the components (a) and (b), but can be further blended. The component (e) is added in an amount of 2 to 30% by weight in the total amount of the composition of the present invention.
It is preferably 5 to 20% by weight. If it is less than 2% by weight, the peeling ability is lowered, while if it exceeds 30% by weight, the corrosiveness to the substrate having the metal film becomes large, which is not preferable.

The present invention is characterized in that the above components (a) to (e) are blended in a specific weight ratio, whereby the exfoliation property of the deteriorated film is excellent, and Al, Cu, Ti, W, etc. While having excellent corrosion prevention effect on the substrate having a metal film, it has the same low viscosity as the conventional resist stripping solution, and further reduces the loss of water due to heating during stripping treatment.
A resist stripping composition having a long stripping life can be obtained.

The resist stripping composition of the present invention can be advantageously used for resists that can be developed with an aqueous alkaline solution, including negative and positive resists. Examples of such a resist include (i) a positive resist containing a naphthoquinonediazide compound and a novolac resin, (ii) a compound that generates an acid upon exposure, a compound that is decomposed by an acid and has increased solubility in an alkaline aqueous solution, and an alkali-soluble compound. A positive resist containing a resin, (iii) a compound that generates an acid upon exposure to light, a positive resist containing an alkali-soluble resin having a group that decomposes by an acid to increase solubility in an aqueous alkaline solution, and (iv) by light Examples thereof include, but are not limited to, a negative resist containing a compound that generates an acid, a crosslinking agent, and an alkali-soluble resin.

[0029]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

Examples 1 to 10 and Comparative Examples 1 to 2 Al of about 1.0 μm was formed as the first layer on a silicon wafer.
A positive photoresist THMR-iP3300 (Tokyo Ohka Kogyo (Tokyo Ohka Kogyo Co., Ltd., which has a -Si-Cu film and a titanium nitride film as a second layer on the first layer) is formed on the substrate and comprises a naphthoquinone diazide compound and a novolac resin. Co., Ltd.) was applied with a spinner and prebaked at 90 ° C. for 90 seconds to form a resist layer having a film thickness of 2.0 μm. This resist layer is NSR-2005i10D
(Nikon Corp.) was used for exposure through a mask pattern, and the resist pattern was formed by developing with a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution. Then, post baking was performed at 120 ° C. for 90 seconds.

Next, a silicon wafer having a first-layer Al-Si-Cu film having a resist pattern formed under the above conditions and a second-layer titanium nitride film on the first layer is used as an etching apparatus TSS-. 6000 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), using a mixed gas of chlorine and boron trichloride as an etchant, etching treatment is performed at a pressure of 5 mmTorr and a stage temperature of 20 ° C. for 168 seconds, and then a mixed gas of oxygen and trifluoromethane is used. , Pressure 20mmT
After-corrosion treatment (treatment for removing chlorine atoms) was performed for 30 seconds at orr and stage temperature of 20 ° C. next,
Ashing device TCA-2400 (Tokyo Ohka Kogyo Co., Ltd.)
Ashing treatment with oxygen gas at a pressure of 0.3 mm Torr and a stage temperature of 60 ° C. for 150 seconds.

The treated silicone wafer was immersed in a stripping solution having the composition shown in Table 1 at 70 ° C. for 10 minutes and then rinsed with pure water. At that time, the peeling state of the ashing residue (peelability of the altered film) and the Al-Si of the first layer
The state of corrosion of the -Cu film and the titanium nitride film of the second layer was evaluated by observing SEM (scanning electron microscope) photographs.

The peelability of the altered film was evaluated as follows.

A: Good peeling state B: Incomplete peeling state The corrosion state was evaluated as follows.

X: No corrosion Y: Corrosion Note that the viscosity of each stripping solution was measured using a B-type rotational viscometer. The results are shown in Table 1.

[0036]

[Table 1] Comparative Examples 3 to 5 Except that the composition of the stripping solution used in Example 1 was changed as shown in Table 2, the strippability and corrosiveness of the altered film were evaluated in the same manner as in Example 1. The viscosity was measured in the same manner. Table 2 shows the results.

[0037]

[Table 2] Example 11 After the stripping solution of Example 1 was left at 70 ° C. for 12 hours, the same silicon wafer as that used in Example 1 was subjected to the same etching treatment, after-corrosion treatment, and ashing treatment as in Example 1. Then, it was immersed at 70 ° C. for 10 minutes, and then rinsed with pure water. At that time, the peeling state of the ashing residue (peelability of the altered film) was evaluated by observing SEM (scanning electron microscope) photographs. As a result, the altered film was completely peeled off. The viscosity of the stripping solution was 8 cP.

Comparative Example 6 The stripping solution used in Example 1 was replaced with a stripping solution comprising 15% by weight of hydroxylamine, 15% by weight of water, 60% by weight of dimethyl sulfoxide and 10% by weight of catechol, and 70% by weight.
After leaving it at 12 ° C. for 12 hours, the same silicon wafer as that used in Example 1 was subjected to the same etching treatment, after-corrosion treatment, and ashing treatment as in Example 1, and then subjected to dipping treatment at 70 ° C. for 10 minutes. Then, rinse treatment was performed with pure water. At that time, the peeling state of the ashing residue (peelability of the altered film) was evaluated by observing SEM (scanning electron microscope) photographs. As a result, the altered film was not completely peeled off. The viscosity of the stripping solution was 8 cP.

[0039]

As described above in detail, according to the present invention, the exfoliation property of the deteriorated film formed by the treatment such as dry etching, ashing and ion implantation under more severe conditions is excellent, and Al, Cu, Ti or It has an excellent effect of preventing corrosion of a substrate on which a metal film such as W is formed, has the same low viscosity as a conventional resist stripping solution, and can reduce the evaporation of water during stripping. It is possible to provide a resist stripping composition having a long life.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisasamu Nakayama 150 Nakamaruko, Nakahara-ku, Kawasaki-shi, Kanagawa Tokyo Ohka Kogyo Co., Ltd.

Claims (3)

[Claims] 1. (a) N, N-diethylhydroxylamine 2 to 30% by weight, (b) hydroxylamine 2 to 4
0% by weight, (c) 10 to 80% by weight of water-soluble organic solvent,
(D) 1-20 wt% anticorrosive, and (e) 2-30 water
A stripper composition for resist, which is composed by weight%. 2. The water-soluble organic solvent (c) is dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone,
The resist stripping composition according to claim 1, which is at least one selected from the group consisting of 1,3-dimethyl-2-imidazolidinone and diethylene glycol monobutyl ether. 3. The (d) anticorrosive agent is an aromatic hydroxy compound, a carboxyl group-containing organic compound or an anhydride thereof,
The resist stripper composition according to claim 1 or 2, which is at least one selected from the group consisting of acetylene alcohol and a triazole compound.